It is harder when you're new to tapestry weaving. But believe me, it is a gremlin that will always follow you. When you have more experience weaving, you just don't notice the gremlin any more. Experience means you adjust for changing conditions constantly without thinking about it.
I wrote a blog post about this with some photo examples last year. You can see that post here:
Weft tension: how to control the amount of weft used in tapestry weaving
Remember this example? The weaver called it her latest catastrophe.
Here is a video about weft tension. I made it for some students in my online classes, but thought the blog readership might also like to see it. As always, you can see the video in larger format on my YouTube channel (just click the YouTube icon in the bottom right corner of the video).
I got a little much-needed help with photographing a new sample for the next online class this week.